I recently upgraded from the Symphony to the Crescendo. I am amazed at the difference between the two machines. I bought the Crescendo primarily for the additional throat space. However, other features I am enjoying on the Crescendo include stadium lighting, an auto threader that never misses, and a walking foot that makes quilting a breeze. In the past, I've done more piecing than quilting, but I quilted a large wall hanging this weekend. I used the Serpentine stitch with metallic thread and had no issues. I was amazed at how smoothly the fabric fed under the walking foot. I'm finding that the Crescendo is so easy to use that I'm sewing a lot more.
Good luck with your decision.